Elliptical spring.



H. A. HOKE.

ELLIPTICAL SPRING.

APPLlCATION FILED JUNE 3. I916.

Patented Dec. 19, 1916.

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UWFET) STATES PATENT @FFTQE.

HARRY A. HOKE, OF ALTOONA, PENNSYLVANIA.

ELLIPTICAL SPRING.

To all whom it may concern Be it known that I, HARRY A. HOKE, a citizenof the United States of America, and a resident of Altoona, in thecounty of Blair and State of Pennsylvania, have invented a certain newand useful Improvement in Elliptical Springs, of which the following isa true and exact description, reference being had to the accompanyingdrawings, which form a part thereof.

My present invention relates to elliptical leaf springs composed of aplurality of spring units arranged side by side, such as are commonlyused inthe trucks of locomotive tenders, and the object of my inventionis to provide simple and effective connecting means which will permit acloser spacing of the different units composing each complete springstructure than has been heretofore practically possible and will at thesame time insure the desired uniformity in the movement and in thedistribution of the load carried by the different units.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, and the advantages possessed by it, reference should be had tothe accompanying drawings and descriptive matter in which I haveillustrated and described a preferred embodiment of my invention.

Of the drawings: Figure 1 is a plan view with parts broken away and insection, of a spring structure embodying my present invention; Fig. 2 isan elevation of the spring structure shown in Fig. 1, with parts brokenaway and in section; and Fig. 3 is a section taken on the line 3-3 ofFig. 2.

The spring structure shown in the drawings comprises three ellipticalspring units proper. Each spring unit consists of an opposing pair ofspring sections A, each in the form of a bunch of spring leaves. Asshown, the two bunches of spring leaves forming each unit are similar toone another, each comprising leaves A, A A A A A", A", A and A". In thepreferred construction illustrated the inner leaves A and A of eachspring section are inturned and the different sections are connectedtogether at their opposite ends by recessed end members B and bolts C asin the con- Specification of Letters Patent.

Application filed June 3, 1916.

Patented Dec. 19, 1916. Serial No. 101,441.

struction disclosed and claimed in my prior Patent No. 1,101,931 grantedJune 30, 1914.

The different leaves of each spring section are held-together midwaybetween the ends of the section, and are connected to the centralportion of the corresponding sections of the other units by an integralconnecting member D, formed of wrought metal or cast steel in ordinarypractice, and provided with a plurality of open ended passages D one foreach spring unit in which the corresponding bunch of spring leaves ofthat unit is received. The walls of each passage D snugly surround thecentra l portion of the bunch of spring leaves passing through it. Inconsequence the central portions of the different leaves composing eachbunch or spring section, are not only firmly held together, but arerigidly connected to the central portions of the corresponding springsections of the different units.

The connection of the different spring units at their centers by theintegral connecting members D gives certain substantialpracticaladvantages over the construction heretofore commonly employed in whichthe bunch of spring leaves forming each spring section have beenconnected at their centers by an individual band surrounding the bunchand separate from the bands surrounding the central portions of theother spring sections. For one thing, my improved construction permitsthe dif ferent spring units to be spaced closer together. than ispossible where individual bands are employed, and in the second place,the use of the present invention insures a more uniform movement of thedifferent spring sections, and a more uniform distrbution of the loadcarried thereby than is had with the individual band construction.

The uniformity of movement and load distribution is obtained not onlybecause of the rigid connection between the central portions of thedifferent spring sections made possible by the use of my improvedconnecting members D, but is enhanced by the closer spacing of thedifferent units, and by the fact that the closer spacing of the unitsmakes the end connections formed by the recessed members Band bolts C,more effective in their tendency to produce uniform action. With the newconstruction the ends of the spring sections may fit snugly between thetransverse websorears B of the members B and these webs or ears need notbe made any thicker than is desirable to give the necessary strength.

The increase in capacity of the spring received in a given space madepossible-by the use of the present invention is peculiarly important inthe case of springs employed in the trucks of locomotive tenders forwhich use my present invention was primarily devised. This follows fromthe factthat on very large tenders it is necessary to usecorrespondingly large axles and others parts, including springs. Anincrease in the width of springs to carry 'the required load increasesthe wheel base of the truck and, therefore,the wheel base of thetender,not only by theamount of increase in the width of the spring, but alsoby the amount of space required for the heavier parts incident to thegreater span between centers of truck wheels. It is also advisable toput the center pins of the trucks of a tender as far apart as possibleas the increase of this distance makes the tender more stable on thetruck. lfthewheel base of thetruck is in creased more trouble is foundwhen overcoming interferences with the-front and back stepsand otherparts on the tender frame if the distance between the truck centersisnot reduced.

In the practical use of the invention I have been able to providealocomotive truck spring in accordance with the present invention, whichis approximately 17 per cent. stronger than a spring occupyingthe samespaceland made with the separate central bands,heretoforeused.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. A spring structure comprising in combination a plurality ofelliptical spring units varranged side by side and each consisting of anopposing pair of bunches of spring leaves, means connecting thedifferent bunches of spring leaves at their opposite ends, and anintegral member connecting one spring leaf bunchof each unit with thecorresponding bunches of the other units and formed with individual openended passages for the different bunches connected by said member, eachof said passages receiving, and the walls thereof closely surroundingthe central portion oft-he corresponding bunch of spring leaves.

2. A spring structure comprising in combination a plurality ofelliptical spring units arranged side by side and each consisting of anopposing pair of bunches of spring leaves, a chambered member ateach'end of the spring structure for connecting the corresponding endsof the different bunches of spring leaves together, said member beingformed with transverse webs interposed between the different units, anda pair of integral members one connecting one spring leaf bunch of eachunit vwith the correspondingbunches of the other units and the othersimilarlyconnecting the other spring leaf bunches, each of said integralmembers be ing formed with individual open ended pas-.

sages for the different bunches connected by 1t, each of said passagereceivlng, and the walls thereof closely surrounding, the cen.

tral portion of the corresponding bunch of spring leaves.

HARRY A. HUKE.

Copies of this patent may be obtained for five cents each, by addressingthe Gommissioner of Patents,

Washington, I). C. a a

